Generation rates and prices to compare for residential and small-business customers are adjusted every three months to reflect the cost of power purchases and adjustments based on customer use in the prior period, PPL said in a news release.

The generation rate for large industrial customers is based on hourly market prices. The company’s price to compare is updated on March 1, June 1, Sept. 1 and Dec. 1 each year.

PPL Electric Utilities does not profit on the generation portion of customers’ bills. It merely passes along the cost of that supply to non-shopping customers without markup, the release said.

PPL serves about 1.4 million customers in Pennsylvania, including more than 430,000 in the midstate.